When I watched a Youtube video in fullscreen it worked fine, but when I turned back from fullscreen to normal, the screen was frozen and I was unable to type anything from my keyboard. I restarted my machine to escape this issue. However, when I see video from videos app or vlc on fullscreen and come back, nothing froze.
I searched, and found some things relating to Chrome or flash, but I found nothing that helped me.
My current system is Ubuntu 16.04, Intel® Core™ i5-3230M CPU @ 2.60GHz × 4, 8GB Ram, and Intel HD 4000.
EDIT The issue happened when I upgraded OpenGL & Mesa. I tried downgrading but the issue wasn't gone. So I must reinstall Ubuntu.
